STUDY MATERIAL · GATE EE · IN
GATE Electrical Machines: questions and notes
Electrical Machines questions from 12 GATE papers (2018–2026) with the official answers, 50 of 52 solved step by step, plus notes for each topic, a formula sheet and practice questions.
- previous-year questions
- 52previous-year questions
- solved step by step
- 50solved step by step
- GATE papers, 2018–2026
- 12GATE papers, 2018–2026
- topics with notes
- 5topics with notes
TOPICS
Five topics, in the order they are taught
Taken from the official GATE 2027 syllabus. Each topic has notes, the formulas you need, its previous-year questions with the official answers, most of them solved step by step, and practice questions.
Transformers: single-phase, three-phase and auto-transformers
Single-phase transformer: the EMF equation, ideal and practical models, referred equivalent circuits and the phasor diagram, open- and short-circuit tests, voltage regulation (including the zero- and maximum-regulation conditions), efficiency, maximum efficiency and all-day efficiency.
14 previous-year questions · 22 marks · 6 practice questions
- GATE EE only
Energy conversion and DC machines
GATE EE study notes on "Energy conversion and DC machines": field energy, coenergy and force/torque in singly and doubly excited systems; DC machine EMF, torque and terminal equations; the separately excited, shunt, series and compound family; generator and motor characteristics, self-excitation and regulation; speed control, starting and braking; losses, efficiency, armature reaction and commutation.
8 previous-year questions · 12 marks · 5 practice questions
- GATE EE only
Three-phase and single-phase induction machines
Study notes for GATE EE, Electrical Machines: three-phase and single-phase induction machines.
17 previous-year questions · 26 marks · 6 practice questions
Synchronous machines
In steady state a synchronous machine runs at exactly n_s = 120f/P, with no slip.
11 previous-year questions · 16 marks · 6 practice questions
- GATE EE only
Losses and efficiency of electric machines
Losses in an electric machine split into two groups.
2 previous-year questions · 3 marks · 5 practice questions
QUESTIONS BY TOPIC AND YEAR
52 questions, by topic and year
How many questions each topic had in the EE and IN papers of each year. This shows what was asked, not what will be asked. We placed each question under a topic ourselves; the exam paper does not label topics. Every question links back to its paper.
| Topic | 2018 | 2020 | 2022 | 2023 | 2024 | 2025 | 2026 | Total |
|---|---|---|---|---|---|---|---|---|
| Transformers | 2 | 2 | · | 2 | 2 | 1 | 5 | 14 |
| DC machines | 2 | 1 | 1 | 3 | · | 1 | · | 8 |
| Induction machines | 1 | 1 | 5 | 3 | 2 | 3 | 2 | 17 |
| Synchronous machines | 1 | 3 | 1 | 1 | 1 | 2 | 2 | 11 |
| Losses & efficiency | · | · | · | · | 2 | · | · | 2 |
GATE EE question papers with solutions: 2026, 2025, 2024, 2023, 2022, 2020, 2018
GATE IN question papers with solutions: 2026, 2025, 2024, 2023, 2022
The 2019 and 2021 papers are not included yet: the copies we host are image scans without the official key.
Electrical Machines formulas by topic
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THE OFFICIAL SYLLABUS
What each paper lists under Electrical Machines
From the GATE 2027 syllabus PDFs: EE Section 5, “Electrical Machines”, and the machines part of IN Section 3, “Electrical Circuits and Machines”. IN lists only single-phase transformers and permanent magnet synchronous machines, so DC machines, induction machines and losses are marked EE only. EC's syllabus has no electrical machines: its only “machines” are finite state machines and machine instructions.
GATE EE
Single phase transformer: equivalent circuit, phasor diagram, open circuit and short circuit tests, regulation and efficiency; Three-phase transformers: connections, vector groups, parallel operation; Auto-transformer, Electromechanical energy conversion principles; DC machines: separately excited, series and shunt, motoring and generating mode of operation and their characteristics, speed control of dc motors; Three-phase induction machines: principle of operation, types, performance, torque-speed characteristics, no-load and blocked-rotor tests, equivalent circuit, starting and speed control; Operating principle of single-phase induction motors; Synchronous machines: cylindrical and salient pole machines, performance and characteristics, regulation and parallel operation of generators, starting of synchronous motors; Types of losses and efficiency calculations of electric machines.
GATE IN
Single phase transformers, permanent magnet synchronous machines
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